How Much Fish Oil Should I Give My Cat in Canada: Dosage by Weight, Safety and Top Picks

Fish oil is one of the most widely discussed omega-3 supplements for cats in Canada, and for good reason. From supporting a healthy skin and coat to promoting joint comfort and cardiovascular function, the potential benefits of fish oil for cats are well-documented. However, many Canadian cat owners are unsure about safe dosing, what form to buy, and which brands are trustworthy. This guide breaks it all down — covering fish oil dosage for cats by weight, safety considerations, and a look at verified supplements and foods available at Ashario Pets in North York, Ontario.

As of 2026, Ashario Pets is a premium pet supply store located at 1111A Finch Ave W, Unit 2, North York, ON M3J 2P7, open 7:00 AM to 11:00 PM daily, 365 days a year. We carry a curated selection of cat health and wellness products, supplements, and omega-3-rich foods from 79+ verified brands.

What Is Fish Oil and Why Do Cats Need Omega-3s?

Fish oil is a dietary supplement derived from fatty fish such as salmon, sardines, anchovies, or mackerel. It is rich in two key omega-3 fatty acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Unlike dogs and humans, cats have a very limited ability to convert plant-based omega-3s (ALA) into usable EPA and DHA, making marine-sourced fish oil a particularly relevant supplement for feline nutrition.

Omega-3 fatty acids play important roles in a cat's body, including supporting skin hydration, coat shine, healthy inflammatory responses, eye development, and cognitive function. Many commercial cat foods — especially dry kibble — are high in omega-6 fatty acids from chicken fat and plant oils, which can create an imbalanced omega-6 to omega-3 ratio over time. Fish oil supplementation can help correct this imbalance when used appropriately.

Always consult a licensed veterinarian before starting any supplement regimen for your cat, particularly if your cat has existing health conditions or is on medication.

Fish Oil Dosage for Cats in Canada: A Weight-Based Guide

Dosage recommendations for fish oil in cats are typically based on total EPA and DHA content — not just the volume of oil in millilitres. Most veterinary nutritionists recommend starting with a conservative dose and adjusting based on your cat's response, always under veterinary guidance.

General dosage guidelines often referenced in veterinary literature include:

• Cats under 5 kg (11 lbs) — approximately 250–500 mg of combined EPA and DHA per day
• Cats 5–7 kg (11–15 lbs) — approximately 500–750 mg of combined EPA and DHA per day
• Cats over 7 kg (15+ lbs) — discuss specific dosing with your veterinarian, as higher doses require professional oversight

These are general reference ranges only. The actual EPA and DHA content per serving varies significantly between products, so always read the supplement label carefully and follow manufacturer instructions or your veterinarian's guidance. Do not assume that one teaspoon of fish oil from one brand equals the same omega-3 content as another.

Explore cat health and wellness products at Ashario Pets to browse verified supplement options available in-store and online.

Forms of Fish Oil Available for Cats

Fish oil supplements for cats come in several forms, each with its own considerations:

• Liquid fish oil — Easy to mix into wet food or raw food; allows for more precise dosing by millilitre
• Soft gel capsules — Convenient for storage and freshness; can be pierced and squeezed over food
• Fish-based wet food — Some wet cat foods naturally contain omega-3-rich fish; not a substitute for targeted supplementation in all cases
• Air-dried and freeze-dried cat food — Certain formulas from brands like ZIWI and Stella & Chewy's incorporate high-quality marine proteins with naturally occurring omega-3s

Liquid fish oil is generally the easiest format to dose accurately for cats. It can be drizzled over meals in small quantities and is typically more palatable to cats than capsules. Store opened fish oil in the refrigerator and discard it by the manufacturer's expiry date to prevent rancidity, which can be harmful.

Is Fish Oil Safe for Cats? What Canadian Owners Should Know

Fish oil is generally considered safe for cats when used at appropriate doses and from reputable sources. However, there are several safety points that Canadian cat owners should be aware of:

• Too much fish oil can be harmful. Excess omega-3 supplementation can interfere with blood clotting, cause digestive upset including diarrhea and vomiting, and contribute to weight gain due to caloric density.
• Vitamin E depletion. High fish oil intake may deplete vitamin E levels over time. Some veterinarians recommend monitoring vitamin E status if supplementing long-term.
• Avoid cod liver oil. Cod liver oil contains high levels of vitamins A and D, which are toxic to cats in large quantities. Stick to standard fish body oil — not liver oil — unless your vet specifically recommends otherwise.
• Source and purity matter. Choose products that are tested for heavy metals, PCBs, and other contaminants. Look for brands that provide third-party testing or have a clear quality assurance process.
• Cats on blood thinners or pre-surgical protocols. Always inform your veterinarian if your cat is receiving fish oil supplementation before any procedure or if they are on anticoagulant medications.

For guidance on choosing the right supplement for your cat's specific health needs, visit best pet food and products for specific needs on the Ashario Pets website.

Top Fish Oil and Omega-3 Supplement Picks Available at Ashario Pets

As of 2026, Ashario Pets carries a range of verified brands that offer cat-appropriate omega-3 supplements and omega-3-rich food options. Here are some of the relevant brands you can find in-store or delivered to your door:

• MOJO Pet Supplements — A trusted supplement brand offering targeted omega-3 and wellness formulas suitable for cats
• Canine Life — Offers supplement blends including omega-3 support designed for companion animals
• Wellytails — A Canadian brand providing omega-rich health supplements formulated for cats and dogs
• ZIWI — Premium air-dried and wet cat food using high-quality New Zealand seafood proteins naturally rich in EPA and DHA
• Stella & Chewy's — Freeze-dried and raw-coated cat food featuring marine proteins that contribute natural omega-3 fatty acids
• Open Farm — A Canadian brand offering responsibly sourced seafood-based cat foods with transparent ingredient sourcing
• Tiki Cat — Wet cat food options featuring fish-forward recipes that provide naturally occurring omega-3s
• The Honest Kitchen — Offers dehydrated cat food with clean, whole-food ingredients including marine sources

Browse the full range of cat products at Ashario Pets, including supplements, wet food, air-dried food, and freeze-dried options for your cat's omega-3 needs.

Signs Your Cat May Benefit From Fish Oil Supplementation

While only a veterinarian can diagnose nutritional deficiencies or determine whether supplementation is clinically appropriate, there are some general signs that cat owners in Canada notice before discussing fish oil with their vet:

• Dull, dry, or flaky coat with excessive shedding
• Dry or itchy skin, especially in winter when Canadian homes are heated and humidity drops
• Stiffness or reduced mobility in older cats (joint support is often discussed in context of omega-3s)
• Cats eating diets heavily based on chicken or plant proteins with limited marine-sourced ingredients

These signs can also indicate other conditions, so a veterinary consultation is always the first step. Explore more about cat wellness needs on the Ashario Pets website for additional educational content.

How to Introduce Fish Oil to Your Cat's Diet

If your veterinarian recommends fish oil for your cat, introducing it gradually tends to produce the best results. Start with a smaller amount than the recommended dose — perhaps half — for the first week, mixed directly into wet food or raw food. Monitor your cat's stool consistency and overall comfort. If no digestive upset occurs, gradually increase to the recommended dose.

Cats can be sensitive to new flavours, though many actually enjoy the taste of fish oil. Mixing it into aromatic wet food or a fish-based topper can help disguise any initial resistance. Consistency matters: supplementing intermittently may not produce the same results as daily, consistent dosing over several weeks.

You can also explore raw cat food options and freeze-dried cat food at Ashario Pets — many of which feature fish-based proteins with naturally occurring omega-3 fatty acids as part of a balanced diet.

Frequently Asked Questions: Fish Oil for Cats in Canada

How much fish oil should I give my cat in Canada?

General veterinary guidance suggests 250–500 mg of combined EPA and DHA per day for cats under 5 kg, and up to 750 mg for cats in the 5–7 kg range. However, dosage depends on the specific product's EPA and DHA concentration and your cat's individual health status. Always consult your veterinarian before starting fish oil supplementation, as they can provide a dose tailored to your cat's weight, diet, and health history.

Can I give my cat human fish oil capsules?

In many cases, plain fish oil capsules formulated for humans — containing only fish oil with no added flavourings, sweeteners, or vitamins like vitamin D or A — are considered safe to use for cats when dosed appropriately. However, avoid flavoured products, enteric-coated capsules, and anything marketed as "cod liver oil," which has an unsafe vitamin A and D profile for cats. A cat-specific or veterinarian-recommended product from a verified brand is always the safer choice.

What is the best fish oil for cats in Canada?

The best fish oil for your cat depends on their individual health needs, dietary baseline, and palatability preferences. Brands like MOJO Pet Supplements, Wellytails, and Canine Life offer cat-appropriate supplement options available at Ashario Pets. Additionally, feeding omega-3-rich cat foods from brands like ZIWI, Open Farm, Stella & Chewy's, or Tiki Cat can help increase your cat's overall omega-3 intake through whole-food sources. Consult your veterinarian for a personalized recommendation and visit top pet product brands in Canada for brand details.

How long does it take for fish oil to work in cats?

Most cat owners and veterinarians note that visible improvements — such as a shinier coat or reduced skin flakiness — typically appear after four to eight weeks of consistent daily supplementation. Internal benefits such as inflammatory support may take longer and are not always visually apparent. Patience and consistency are key, and regular check-ins with your veterinarian help ensure the supplementation is achieving the desired outcome.

Where can I buy fish oil supplements for my cat in North York?

Ashario Pets at 1111A Finch Ave W, Unit 2, North York, ON M3J 2P7 carries a selection of cat health and wellness supplements, including omega-3 products from verified brands. The store is open 7:00 AM to 11:00 PM every day of the year, including holidays. You can also order for delivery through Uber Eats, DoorDash, SkipTheDishes, Instacart, or Fantuan. Contact Ashario Pets at +1-647-564-4433 for product availability questions.

Visit Ashario Pets for Cat Supplements and Omega-3 Products in North York

Ashario Pets is a premium pet supply store in North York, Ontario, dedicated to helping Canadian pet owners make informed, high-quality choices for their cats and dogs. Whether you are looking for a targeted fish oil supplement, a fish-forward wet cat food, or an air-dried formula packed with marine proteins, our team can help guide your selection from our extensive range of verified brands.

Explore our cat health and wellness collection, browse our cat blog for more educational content, or check out our pet store FAQ for information on delivery, store hours, and product availability. For cat owners across North York, Vaughan, Etobicoke, and the greater Toronto area, Ashario Pets is your trusted source for premium cat nutrition and care products — open every day from 7:00 AM to 11:00 PM at 1111A Finch Ave W, Unit 2, North York, ON.